1. Field of the Invention
The present invention relates to an object, a method, or a manufacturing method. The present invention relates to a process, a machine, manufacture, or a composition of matter. In particular, the present invention relates to, for example, a display device, a light-emitting device, or a driving method thereof; and a semiconductor device, a display device, or a light-emitting device each including a transistor, or a driving method thereof. The present invention relates to an electronic appliance including the semiconductor device, the display device, or the light-emitting device.
In this specification, the semiconductor device indicates all the devices that can function by utilizing semiconductor characteristics. A display device, an electro-optical device, a semiconductor circuit, an electronic device, and the like may include a semiconductor device.
2. Description of the Related Art
In recent years, a transistor that includes an oxide semiconductor film containing indium, gallium, and zinc has attracted attention.
A transistor including an oxide semiconductor film is known to have extremely low leakage current in an off state. For example, a low-power semiconductor device and the like utilizing the low leakage current of a transistor including an oxide semiconductor film and the high on-state current of a silicon transistor are disclosed (see Patent Document 1).